The Earthquake in 2004 triggered Tsunami of great proportions which caused immense damage to property and people was a lighter one than the one that occurred on 11 April 2012.

Though it was feared initially that this will cause Tsunami of great proportions which made the ptwc issue Tsunami alert for as many as 28 countries,the alert was withdrawn.

Barring a small Tsunami in Thailand(see by blog on this), no major Tsunami has been reported nor very serious damage done to properties.

Why?

Location of the earthquake.

“The first temblor, a magnitude 8.6 quake, struck at 2:38 p.m. local time, along a segment of a fault on the sea floor some 269 miles southwest of the coastal city of Banda Aceh, capital of Aceh province. A second, 8.2 magnitude quake struck two hours later roughly 120 miles south of the first quake’s epicenter.

So far, the quakes appear to have done little damage and caused no fatalities, although people felt the shaking as far away as the east coast of India. In Banda Aceh, many residents streamed into the streets when the shaking began, according to press reports from the city.

Memories of the disastrous December 2004 earthquake and tsunami remain fresh. The event left 230,000 dead throughout the Indian Ocean basin as the tsunami in some locations reached heights of up to 90 feet.

Though both of Wednesday’s large quakes join the magnitude 9.1 event in 2004 event as “great” earthquakes – the strongest of six categories – the initial temblor Wednesday reportedly pushed only a 30-inch-high surge of water onto Indonesia‘s west coast.

In addition, the 2004 event released nearly six times as much energy as the first quake that struck on Wednesday and some 22 times more energy than the second.

The difference? Location, suggests Amy Vaughan, a geophysicist with the National Earthquake Information Center.

The 2004 rupture occurred along the northern reaches of a subduction zone that hugs the west coast of Indonesia and defines the arc of Indonesia’s islands.

The quake occurred in a section of the zone where a vast patch of crust known as the Indian plate is sliding beneath the much smaller Burma plate. Quakes along such subduction zones tend to generate the planet’s most violent temblors because the surface areas sliding past each other are large.

Researchers estimate that the patch of the subduction zone affected in the 2004 quake covered an area roughly the size of California. The amount of slip along the length of this patch was 50 feet.